Hyperbaric oxygen treatment is used in the treatment of medical disorders involving the need for increased amounts of oxygen by the human body. Traditionally, hyperbaric oxygen has been used to treat divers suffering from caisson disease, otherwise known as the "bends". A decompression sickness is a condition requiring reduction and reabsorption of trapped nitrogen gas bubbles in the circulatory system by increasing ambient pressure in the patient and facilitating more rapid removal of dissolved nitrogen by slow decrease to normal atmospheric pressure under a 100% oxygen environment.
Various other uses of hyperbaric oxygen treatment have been discovered over the last few years including the treatment of gangrene, carbon monoxide intoxication, skin grafts, decompression sickness, smoke inhalation, Meleney's ulcers and chronic refractory osteomyelitis. Hyperbaric oxygen has also been found effective in treating cancer patients suffering from skin disorders caused by radiation therapy. Many other bodily malfunctions relating to oxygen deficiencies have responded favorably to hyperbaric oxygen treatment alone and in combination with conventional treatments.
Hyperbaric oxygen causes beneficial effects by increasing the delivery of oxygen to the blood and tissues. The increased physical pressure also has been found to have a positive effect on the body. Under normal atmospheric pressure, only a small amount of oxygen is dissolved in the bloodstream. When oxygen is administered at an elevated pressure, a higher alveolar partial pressure of oxygen is achieved because more oxygen is dissolved. This effect combined with the effect of the increased physical pressure leads to physiologic changes including changes in the patient's microcirculation and platelet aggregation, immune mechanism, and bacterial metabolism. For example, many organisms, such as Clostridium perfringens that causes gas gangrene, can't survive in high concentrations of oxygen. Hyperbaric oxygen therapy also tends to decrease inflammation, and increase the rate of healing at the sight of an injury. Also, blood vessels appear to grow better at higher oxygen concentrations making skin grafts more successful.
Hyperbaric chambers have been available for many years; however, access to the chamber is often impeded because the patient must climb into the chamber and lie prone or supine within the chamber for extended periods of time while treatment is being administered. Oftentimes treatment is continued for hours or even days. This inability to change position causes discomfort for the patient and may even cause claustrophobia. Thus, there has been a need in the art for a hyperbaric chamber which enables the patient to assume a variety of positions within the chamber.
Typical of the chambers described in the prior art is U.S. Pat. No. 3,368,556. The chamber described in this patent has a door with a complex locking system comprising pivot rods and latching systems. The door is difficult to open and close quickly.
A further disadvantage of hyperbaric chambers in the prior art is pressure leakage. Due to the increased pressure within the chamber, all openings and joints must be sealed to prevent such leakage. The entry hatch is the prime location of pressure leakage. Hyperbaric chambers have utilized a variety of locks and seals to curtail pressure leakage around the entry hatch, but these closures have provided seals which are unsatisfactory.
Finally, the hyperbaric chambers that are described in the prior art all have hatches that are difficult or impossible to open from the inside of the chamber. Thus, there has also been a need in the art for a hyperbaric chamber with a hatch that is both easy to open from inside or outside the chamber. The hatch must also provide an air-tight seal so that a superatmospheric pressure can be maintained within the chamber.